As a mobile display-related industry using touch screens such as smartphones and tablet PCs develops, a next-generation touch screen has been demanded, and many studies thereof have been carried out. In particular, a study of an electrosensory haptic touch screen capable of recognizing a user's touch by generating an electric field on a screen has been carried out.
U.S. Patent Laid-open Publication No. US2011/0109588 (entitled “Tactile stimulation apparatus having a composite section comprising a semiconducting material”) describes a configuration of an electrosensory haptic touch screen. The electrosensory haptic touch screen described in US2011/0109588 can be used by being closely pressed on a general capacitive touch screen.
FIG. 1 is an explanatory diagram of an electrosensory haptic touch screen. Referring to FIG. 1, the electrosensory haptic touch screen includes a semiconductor layer 20 substantially serving as an electrode and an insulating layer 30 stacked on the semiconductor layer 20 and configured to prevent an electric current flow generated by a touch input device such as a finger on the semiconductor layer 20. Such an electrosensory haptic touch screen may be provided on a conventional capacitive touch screen 10 as depicted in FIG. 1.
If the electrosensory haptic touch screen is provided on the capacitive touch screen 10, the electrosensory haptic touch screen and the capacitive touch screen 10 generally cannot be operated in optimal conditions for display use.
Further, when the electrosensory haptic touch screen is touched by a user, electric charges are accumulated on the insulating layer 30. Since the electric charges are accumulated on the insulating layer 30, an overall function of the electrosensory haptic touch screen may be deteriorated.
The electrosensory haptic touch screen including the semiconductor layer 20 and the insulating layer 30 is integrally manufactured with the capacitive touch screen 10. Therefore, if the electrosensory haptic touch screen malfunctions, a consumer needs to replace the capacitive touch screen 10 as well as the electrosensory haptic touch screen, which is a financial burden to the consumer.
Furthermore, the electrosensory haptic touch screen described in US2011/0109588 cannot be applied to a pliable or bendable touch screen due to its problem of flexibility.